1. Field of the Invention
This invention relates to a remote instruction system that an instruction can be given remotely by means of an image.
2. Description of the Related Art
In a remote repair system, remote maintenance system, remote medical care system, remote conferencing, and the like, for example, various instructions in operation procedure need to be given to a real thing from a remotely located position. As one of remote instruction systems where the instructions can be given to the real thing from the remote location, for example, U.S. Patent Application Publication No. 2004/0070674 describes a technique of sending a moving image to a remote terminal while a subject or target existent on the real thing side is being captured by a camcorder, and projecting an annotation image onto the subject by means of a projector on the real thing side, the annotation image being designated on the basis of the captured image on the remote terminal.
In the above-described remote instruction system, however, when a projection position of an annotation image onto a subject is changed according to an instruction given by a remote terminal, a range in which the projection position can be changed is limited to one being displayed on a display screen of the remote terminal, namely, a range which is captured by a camcorder. Therefore, if the annotation image is to be projected onto outside the afore-described range, it is necessary to give an instruction verbally to the operator or viewer who are existent on the subject side to change the position of the subject. If the position of the subject relative to the camcorder is changed, the projection position onto the subject projected by the projector has to be changed accordingly. At this time, three-dimensional positional information of the subject relative to the projector is necessary. However, it is not easy to obtain the three-dimensional positional information of the whole subject accurately. Accordingly, it is difficult to change the projection position of the annotation image precisely.